diff --git a/koptilnya/libs/table.txt b/koptilnya/libs/table.txt
index d48056f..ec4dbed 100644
--- a/koptilnya/libs/table.txt
+++ b/koptilnya/libs/table.txt
@@ -57,18 +57,18 @@ end
 function table.map(tbl, action)
     local res = {}
 
-    for _, field in ipairs(tbl) do
-        table.insert(res, action(field))
+    for idx, field in ipairs(tbl) do
+        table.insert(res, action(field, idx))
     end
 
     return res
 end
 
-function table.filter(tbl, predicate)
+function table.filter(tbl, filterFunc)
     local res = {}
 
-    for _, field in ipairs(tbl) do
-        if predicate(field) == true then
+    for idx, field in ipairs(tbl) do
+        if filterFunc(field, idx) == true then
             table.insert(res, field)
         end
     end
@@ -84,13 +84,11 @@ function table.find(tbl, predicate)
     end
 end
 
-function table.reduce(tbl, func, init)
-    init = init or 0
-
+function table.reduce(tbl, reducer, init)
     local accum = init
 
-    for _, field in ipairs(tbl) do
-        accum = accum + func(field)
+    for idx, field in ipairs(tbl) do
+        accum = reducer(accum, field, idx)
     end
 
     return accum